The number of significant figures will be four (4)
How much does the mass of 12.65-g sample of copper(II) nitrate hexahydrate decrease when heated?
Molar mass calculation for Cl^2
Answer:
Mass of Cl = 35.5
Mass of Cl2 => 35.5×2
=> 71 g/mol
hope that helps ✌
71
explain:The atomic mass of chlorine is equal to the molar mass of chlorine so the molar mass of chlorine is 35.5
=> molar mass for Cl^2: 35,5*2=71
Between volume and mass which gives a larger source of error in the determination of density? Explain why.
Answer:
volume gives a larger source of error in determination of density
Answer:
Density and volume are inversely proportional. The greater the volume, the lower the density.
Density= Mass/ Volume
Explanation:
What is Density?Density= Mass/ Volume
A volume error may be due to the measuring instrument used. Different instruments have different resolutions, and therefore varying percentage uncertainties. An instrument with a higher resolution has a lower percentage error. A pipette will give a more accurate reading compared to a beaker. Density and volume are inversely proportional. The greater the volume, the lower the density.
Parallax error could also lead to inaccurate volume readings. The volume reading must be taken below the meniscus for a liquid such as water and above the meniscus for a liquid such as mercury.
Another source of error is the measurement of mass. Instruments that are used to determine mass have different percentage uncertainties. An electronic weighing scale is most likely to give an accurate reading. Density is directly proportional to mass. The greater the volume of the liquid, the greater its density.
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cho hỗn hợp gồm alcl3 và fecl3 trình bày cách tách từng muối riêng ra khỏi hỗn hợp
Answer:
ném NaOH vào thì th AlCl3 tan hết còn lại kết tủa Fe(OH)3 lần.
Lọc kết tủa riêng phần dung dịch tan riêng
Rồi Cho HCl vô lại là xong
Explanation:
Water is dipolar because:
A. It has two hydrogens, each of which pulls oxygen's electrons and separates the
charges into two areas.
B. Oxygen pulls electrons closer to itself than hydrogens, giving the oxygen a
slight negative and hydrogens a slight positive charge.
C. Oxygen pulls electrons closer to itself than hydrogens, giving the oxygen a
slight positive and hydrogens a slight negative charge.
OD. It has two hydrogens, each of which has its own polar area.
Answer:
B. Oxygen pulls electrons closer to itself than hydrogens, giving the oxygen a slight negative and hydrogens a slight positive charge.
Explanation:
In the water molecule (H2O), an oxygen atom is bonded to two hydrogen atoms. Oxygen atom is much more electronegative (has more attraction for electrons) than hydrogen atom, hence, it pulls electrons from one one of the hydrogen atoms bonded to it making it more negatively charged and the hydrogen atom, more positively charged.
The possession of positive charge (+) and negative charge (-) in the same molecule, caused by uneven flow of electrons is what it means to be DIPOLAR (from dipole). Hence, water is DIPOLAR because oxygen pulls electrons closer to itself than hydrogens, giving the oxygen a slight negative and hydrogens a slight positive charge.
A student is asked to convert measurements from meters to millimeters and from millimeters to meters. His answers are
shown in bold in the choices shown below. On which choite did he make a mistake?
9070 mm = 90.7 m
652,222 mm= 652.222 m
37,500 mm = 37.5 m
1.02 x 106 mm = 1020 m
Answer:
The first one
Explanation:
9070 mm = 90.7 m
9070mm is actually equal to 9.07m
6c.Calculate the maximum volume, in dm3, of chlorine gas at Stp that can be obtained from 23.4 tonnes of molten sodium chloride. 1 tonne= 10^6 Mr of NaCl=58.5 molar volume of chlorine at stp= 24dm3 Give your answer in standard format.
Answer:
4.48×10⁶ dm³
Explanation:
We'll begin by converting 23.4 tonnes to grams (g). This can be obtained as follow:
1 tonne = 10⁶ g
Therefore,
23.4 tonnes = 23.4 × 10⁶
23.4 tonnes = 2.34×10⁷ g
Thus, 23.4 tonnes is equivalent to 2.34×10⁷ g
Next, we shall determine the number of mole in 2.34×10⁷ g of NaCl. This can be obtained as follow:
Mass NaCl = 2.34×10⁷ g
Molar mass of NaCl = 58.5 g/mol
Mole of NaCl =?
Mole = mass / molar mass
Mole of NaCl = 2.34×10⁷ / 58.5
Mole of NaCl = 4×10⁵ moles
Next, we shall determine the number of mole of chlorine, Cl₂ produced from the reaction. This can be obtained as follow:
2NaCl —> 2Na + Cl₂
From the balanced equation above,
2 moles of NaCl reacted to produce 1 mole of Cl₂.
Therefore, 4×10⁵ moles of NaCl will react to produce = (4×10⁵ × 1)/2 = 2×10⁵ moles of Cl₂.
Thus, 2×10⁵ moles of Cl₂ were obtained from the reaction.
Finally, we shall determine the volume of Cl₂ produced. This can be obtained as follow:
1 mole of Cl₂ at stp = 22.4 dm³
Therefore,
2×10⁵ moles of Cl₂ at stp = 2×10⁵ 22.4
2×10⁵ moles of Cl₂ at stp = 4.48×10⁶ dm³
Thus, the volume of chlorine obtained from the reaction is 4.48×10⁶ dm³
In ionic bonding Question 41 options: the electrons are shared between the atoms. the process of forming an ionic bond is highly endothermic overall. the bonding that occurs is usually between two nonmetal atoms. a noble gas configuration is formed for each element or ion. At least two of the above statements are correct.
Answer: In ionic bonding (a noble gas configuration is formed for each element or ion).
Explanation:
IONIC bonding, which is also called electrovalent bonding involves the complete transfer of electrons from one atom to another in order to attain a noble gas electron configuration.
The noble gases or group 0 elements have a completely filled outermost shell of eight electrons. This makes them generally very stable, that is, unreactive. There is a natural drive for other atoms to attain the electron configuration of group 0 (inert gases) elements. This usually results in atoms entering into chemical combinations by losing, gaining or sharing electrons.
Ionia compound such as sodium chloride
--> have high melting points because alot of heat energy is required to break the attractive forces between the ions;
--> are hard and brittle;
--> are soluble in water;
--> conduct electricity when in solution or molten form because the ions are able to move about, that is, they are electrolytes
please hurry which statement is a scientist most likely to use in describing work
What mass of helium gas (in g) occupies 15.3 L at STP?
Answer:
[tex]\boxed {\boxed {\sf 2.73 \ g \ He}}[/tex]
Explanation:
We are asked to find the mass of helium gas given a volume.
1. Convert Liters to Moles1 mole of any gas occupies a volume of 22.4 liters. So, 1 mole of helium gas contains 22.4 liters of helium. Create a ratio using this information.
[tex]\frac {1 \ mol \ He }{ 22.4 \ L \ He}[/tex]
We are converting 15.3 liters of gas to moles, so we multiply by that value.
[tex]15.3 \ L \ He *\frac {1 \ mol \ He }{ 22.4 \ L \ He}[/tex]
The units of liters of helium (L He) cancel.
[tex]15.3 *\frac {1 \ mol \ He }{ 22.4}[/tex]
[tex]\frac {15.3}{22.4} \ mol \ He[/tex]
[tex]0.6830357143 \ mol \ He[/tex]
2. Convert Moles to GramsThe molar mass is the mass of 1 mole of a substance. These values are found on the Periodic Table as atomic masses, but the units are grams per moles. Look up the molar mass of helium.
He: 4.0026 g/molCreate another ratio using the molar mass.
[tex]\frac {4.0026 \ g \ He}{1 \ mol \ He}[/tex]
Multiply by the number of moles we calculated.
[tex]0.6830357143 \ mol \ He *\frac {4.0026 \ g \ He}{1 \ mol \ He}[/tex]
The units of moles of helium (mol He) cancel.
[tex]0.6830357143*\frac {4.0026 \ g \ He}{1 }[/tex]
[tex]2.73391875 \ g \ He[/tex]
3. RoundThe original measurement of volume has 3 significant figures, so our answer must have the same.
For the number we calculated, that is the hundredths place.
The 3 in the thousandths place to the right (2.73391875) tells us to leave the 3 in the hundredths place (2.73391875).
[tex]2.73 \ g \ He[/tex]
15.3 liters of helium gas is approximately 2.73 grams of helium.
Mass of A = 320 g
Volume of A= 64 cm3
A
Density of B = 3 g/cm3
Volume of B = 27 cm3
(Not drawn to scale)
11
22. What is the density of cube A?
A) 0.2 g/cm3 B) 5.0 g/cm3
C) 12.8 g/cm D) 64.0 g/cm3
Answer:
Mass of A=320g
Volume of A=64cm3
Density of B =3g/cm3
Volume of B = 27 cm3
(Not drawn to scale)
and the density of cube A =5.0g/cm3
Please mark me a brainlist
The density of the object that has been labelled as A from the calculation is 5.0 g/ [tex]cm^3[/tex]. Option B
What is the density?
Density is a physical property of matter that measures how much mass is contained within a given volume.
Density is a fundamental property of matter that describes how mass is distributed within a given volume. It is a useful parameter in various scientific, engineering, and everyday applications.
We know that;
Density = Mass/Volume
= 320 g/64 [tex]cm^3[/tex]
= 5.0 g/ [tex]cm^3[/tex] as seen here
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I’m screwed omg i totally forgot I have school today and forgot to do this someone help me rq I’ll brainlist plslsls be awake just make sure you write the word equation for each of the following metal oxidation reactions or if you can, also write a chemical equation below it. idrm bout that but it’ll be really nice if u did.
tried doing it and if ur one of the smart people that can do science unlike me surely u’ll help. ☺️
Answer:
Zn + O2 = ZnO
Mg + O2 = MgO
Cu + O2 = CuO
Al + O2 = Al2O3
Explanation:
What is the purpose of a catalyst in the production of hydrogen?
Select the correct answer.
- to increase the rate at which water molecules decompose
- to decrease the amount of oxygen produced
- to decrease the temperature of the reaction
- to increase the activation energy of the reaction
The purpose of a catalyst in the production of hydrogen is to increase the rate at which water molecules decompose.
What is a catalyst-A catalyst is a substance that increases the rate of a chemical reaction without itself being consumed or produced during the reaction. As a result, catalysts assist in speeding up chemical reactions while also decreasing the amount of energy needed for the reaction to occur. In hydrogen production, catalysts are used to speed up the decomposition of water into hydrogen and oxygen. The use of catalysts lowers the activation energy required for the reaction to occur, resulting in a faster reaction rate and lower operating temperatures.What is the process of hydrogen production?Hydrogen production has various methods, and one of the most commonly used methods is water electrolysis. In this method, water molecules are split into hydrogen and oxygen using an electric current passed through an electrode. Water is broken down into hydrogen and oxygen during the process, with the assistance of a catalyst. During this process, a catalyst like platinum or nickel is employed to speed up the chemical reaction of water decomposition.
When an electric current is applied to the catalyst, water molecules are broken apart, releasing hydrogen and oxygen atoms.Catalysts lower the activation energy of the reaction, allowing it to occur faster than it would otherwise. In hydrogen production, catalysts are crucial since they enable the reaction to occur at a lower temperature, reducing energy consumption and minimizing operating costs. As a result, the use of catalysts is essential to the production of hydrogen.
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solubility of salt at 10 degree Celsius is 20 how does it what does it means what happens if the temperature of saturated solution is increased and decreased explain it in detail
Answer:
solubility of salt at 10 degree Celsius is 20 how does it what does it means what happens if the temperature of saturated solution is increased
Explanation:
solubility of salt at 10 degree Celsius is 20 how does it what does it means what happens if the temperature of saturated solution is increased
what do you mean by acceleration due to gravity of a body is 10 metre per second square
Answer:
If a body is accelerated by 10m/s^2, it means that the body's speed (or velocity to be precise) is increasing by 10m/s every second. That is, if the initial ...
hii pls help me to balance the equation thanksss
Answer:
I hope the link above will be helpful
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
[tex]\boxed{\pmb{\green{\sf{3Mg(s) + N_{2}(g)\dashrightarrow Mg_{3}N_{2}(s)}}}}[/tex]
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
Sodium nitrate is used in fertilizers, explosives, and glass manufacturing. Give the formula for this compound
How many moles are in 1.7 g of sodium nitrate?
Explanation:
The molecular formula for Sodium Nitrate is NaNO3. The SI base unit for amount of substance is the mole. 1 grams Sodium Nitrate is equal to 0.011765443644878 mole.
Under certain conditions, the substance mercury(II) oxide can be broken down to form mercury and oxygen. If 24.1 grams of mercury(II) oxide react to form 22.3 grams of mercury, how many grams of oxygen must simultaneously be formed? Grams oxygen
Answer:
1.76 g
Explanation:
2HgO(s) ==> 2Hg(l) + O2(g)
Number of moles of Hg = 22.3 g/ 201g/mol
= 0.11 moles
From the reaction equation;
2 moles of Hg is formed alongside 1 mole of oxygen
Hence;
0.11 moles of Hg forms 0.11 moles × 1/2
= 0.055 moles of oxygen
Mass of oxygen formed = 0.055 moles of oxygen × 32g/mol = 1.76 g
someone who’s good with science this is for you btw I’ll brainlist and rate 5 star due today.
Write the word equation for each of the following metal oxidation reactions also the chemical equations below it.
1) Osmium reacts with oxygen in the air to form a highly toxic chemical called osmium oxide
+=
+=
Answer:
Solid Osmium transition metal reacts with Oxygen gas to produce solid Osmium tetroxide.
Os(s) + 2O₂(g) -> OsO₄(s)
Explanation:
Osmium tetroxide is another way of writing Osmium (VIII) oxide.
Leaving powdered osmium exposed to air in a room will slowly create osmium tetroxide at room temperature.
Similarly, osmium tetroxide vapor will readily be released from a liquid solution at room temperature.
Read the chemical equation.
2H2 + O2 → 2H2O
Which of the following statements would be correct if one mole of H2 was used in this reaction?
One mole of oxygen was used in this reaction.
Two moles of oxygen were used in this reaction.
One mole of water was produced from this reaction.
Two moles of water were produced from this reaction.
WILL MARK BRAINLIST
Answer:
One mole of water was produced from this reaction.
Explanation:
According to this question, the following equation is given as follows:
2H2 + O2 → 2H2O
Two (2) moles of hydrogen gas produces two (2) moles of water in this balanced chemical equation.
If 1 mole of hydrogen gas was used, then:
1 × 2/2 moles of water would be produced
1 mole of water would be produced.
Answer:
One mole of water was produced from this reaction.
Explanation:
Guy above me is right
Which compound in 1 mol/dm3 solution has the highest PH value? a) Ethanoic acid b) Sodium chloride c) Sodium hydroxide d) Hydrogen chloride
Answer:
Explanation:
A. Ethanoic acid-acetic acid being weak acid dissocated weekly and turns solution to weakly acidic, ph will be between 4-7,
B. Hydrochloric acid - the solution would be acidic- with lots of H+ ions, Ph will be between 1-4,
C. Sodium chloride - solution prodcued netural Na+ and Cl- hence wont affect ph of solution will be equalt to 7.
D. Sodium hydrogen carbonate-NaHCO3 is weak base and the PH will be above 7,
help pls I will mark brainlest
Resources found in lithosphere: gold and iron etc
Resources found in atmosphere: Water vapor, gases etc.
How many g of water are required to be mixed with 11.75 g of HgCl in order to make a 0.01 m solution? (Refer to the periodic table for atomic weights.)
a.) 40 g
b.) 5,000 g
c.) 2 x 10^8 g
d.) 2 x 10^6 g
The general name for a substance added to a reaction that affects the rate but is not consumed in the reaction is called a_____.
a.)constituent
b.)catalyst
c.)complex
d.)reactant
The action of a catalyst can be explained in the following manner:
a.) The catalyst makes it possible for the reaction to take place by another path that makes possible reaction at a lower energy.
b.) The catalyst takes no part in the reaction but serves as a buffer between reactants and products.
c.) The catalyst prevents the reverse reaction.
d.) The catalyst lowers the temperature of the reactants.
The energy level necessary to enable a reaction to occur is called the_____ energy.
a.) potential
b.) kinetic
c.) activation
d.) nuclear
Raising the temperature of a reacting system increases the rate of the reaction, but does NOT increase the:
a.) number of collisions
b.) average velocity of the reacting particles
c.) activation energy
d.) vibrational motions within the molecules
e.) fraction of the reacting particles which possess energies greater than the activation energy
Answer:
5,000 g
b.)catalyst
The catalyst makes it possible for the reaction to take place by another path that makes possible reaction at a lower energy.
activation
activation energy
Explanation:
Formulae for molality = number of moles of solute/mass of solvent in kilograms
Number of moles of solute= 11.75g/236 g/mol = 0.0498 moles
0.01 = 0.0498/x
x= 0.0498/0.01
x= 5 Kg or 5000 g
A catalyst refers to any substance that alters the rate of reaction but remains unaffected at the end of the reaction. The catalyst lowers the activation energy of a reaction.
For a chemical reaction to occur, the substances participating in that reaction must possess energy which is greater than the activation energy of the reaction. The activation energy is a sort of energy barrier between reactants and products which must be surmounted before a reaction can take place.
When the temperature of a reaction system is raised, the molecules move faster and the number of effective collisions in the system increases. However, raising the temperature does not raise the activation energy of the system.
what is the volume of 0.284g of carbon dioxide at STP ??
Answer:
Explanatio
NCO2= 0, 248 /44= 0 ,005636
VCO2= 0,005636* 22,4= 0 ,126254545
What is the pressure in atm exerted by 1.8 g of H2 gas exert in a 4.3 L balloon at 27ºC? R = 0.821(L*atm) / (mol*K)
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The pressure in atm exerted by 1.8 g of H₂ gas exert in a 4.3 L balloon at 27ºC is 5.12 atm
What is Ideal gas law ?The ideal gas law (PV = nRT) relates the macroscopic properties of ideal gases. An ideal gas is a gas in which the particles (a) do not attract or repel one another and (b) take up no space (have no volume).
Let's convert grams to moles (via molar mass).
Molar Mass (H₂) : 2 (1.008 g/mol)
Molar Mass (H₂) : 2.016 g/mol
1.8 grams H₂ 1 mole
---------------------- x ---------------------- = 0.893 moles H₂
2.016 grams
The Ideal Gas Law equation looks like this:
PV = nRT
In this equation,
P = pressure (atm) V = volume (L) n = moles R = Ideal Gas Constant (0.0821 L*atm/mol*K)T = temperature (K)After converting Celsius to Kelvin, you can put the given values into the equation and simplify to find the pressure.
P = ? atm R = 0.0821 L*atm/mol*K
V = 4.3 L T = 27 °C + 273.15 = 300.15 K
n = 0.893 moles
PV = nRT
P (4.3 L) = (0.893 moles) (0.0821 L*atm/mol*K)( 300.15 K)
P (4.3 L) = 22.0021
P = 5.12 atm
Therefore, The pressure in atm exerted by 1.8 g of H₂ gas exert in a 4.3 L balloon at 27ºC is 5.12 atm
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Heat transfer takes place when:
A. there is a temperature difference.
B. conduction or convection occurs, but not radiation.
OC. thermal energy is present.
D. None of these
Answer:
A. There is a temperature difference
Explation:
Whenever there is a temperature difference, heat transfer occurs. Heat transfer may occur rapidly, such as through a cooking pan, or slowly, such as through the walls of a picnic ice chest.
Answer:
A.) there is a temperature difference
Explanation:
I got it correct on founders edtell
What's a third reaction? (Chemistry)
Explanation:
a chemical reaction in which the rate of reaction is proportional to the concentration of each of three reacting molecules
hii pls help me to balance the equation thanksss
Explanation:
2KCLO3 (s) = 2KCl (s) + 3O2 (g)
describe the location of the Philippines
Answer:
Philippines, island country of Southeast Asia in the western Pacific Ocean. It is an archipelago consisting of more than 7,000 islands and islets lying about 500 miles (800 km) off the coast of Vietnam. Manila is the capital, but nearby Quezon City is the country's most-populous city.
1125 J of energy is used to heat 250 g of iron to 55 °C. The specific heat capacity of iron is 0.45 J/(g·°C).
What was the temperature of the iron before it was heated?
55 °C
55 °C
35 °C
35 °C
45 °C
45 °C
20 °C
Answer:
45 °C.
Explanation:
From the question given above, the following data were obtained:
Heat (Q) = 1125 J
Mass (M) = 250 g
Final temperature (T₂) = 55 °C
Specific heat capacity (C) = 0.45 J/gºC
Initial temperature (T₁) =?
The initial temperature of the iron can be obtained as illustrated below:
Q = MC(T₂ – T₁)
1125 = 250 × 0.45 (55 – T₁)
1125 = 112.5 (55 – T₁)
Divide both side by 112.5
1125/112.5 = 55 – T₁
10 = 55 – T₁
Collect like terms
10 – 55 = –T₁
–45 = –T₁
Multiply through by –1
45 = T₁
T₁ = 45 °C
Therefore, the initial temperature of the iron is 45 °C
